Modular catalyst bed support

ABSTRACT

A modular catalyst bed support can be used to increase the number of catalyst beds available in a reactor. The modular catalyst bed support can include a lattice with a plurality of lattice openings and modules inserted into the lattice openings. The modular catalyst bed support can rest on top of an underlying catalyst bed, which can reduce or eliminate the need for attachment of the modular catalyst bed support to the walls of the reactor.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application Ser.No. 61/453,214 filed Mar. 16, 2011, which is herein incorporated byreference in its entirety.

FIELD OF THE INVENTION

Structures and methods are described below for adding a catalyst bed toa reactor.

BACKGROUND OF THE INVENTION

Reactors for petroleum refining can remain viable from a structuralstandpoint for multiple decades. However, during this lengthy timeperiod, advancements in refining technology may lead to improved designsor methods that do not match the original reactor structure. Systemsand/or methods that allow older reactors to be upgraded to takeadvantage of newer technologies can result in substantial cost savings,in comparison with retiring a reactor and building a new structure.

Many conventional or heritage catalytic reactors for petroleum refiningare single bed reactors. Some of these reactors can have long reactorbeds relative to the inner diameter of the reactor. For example, a ratioof the length of the reactor bed to the inner diameter of the reactorcan be at least about 4 to 1 or greater. Although the long reactor bedcan hold a large volume of catalyst, the single bed configuration canlead to reduced catalyst effectiveness.

One reason for reduced catalyst effectiveness can be poor flowdistribution. A poor flow distribution can develop within a catalyst bedfor a variety of reasons. The length of the catalyst bed can be onefactor, with longer beds typically having an increased likelihood offlow distribution problems. Another problem can be having a low liquidmass flux through the bed, where the amount of liquid flowing throughthe bed per unit area and per unit time is too low to provide good flowcharacteristics. Other factors that can contribute to a poor flowdistribution can be related to flow bridging within the bed, poorloading of catalyst into the catalyst bed, or liquid plugging. Anexample of a poor flow distribution can be “channeling” of a feed, wherethe feed preferentially passes through a portion of the catalyst whileexposing other portions of the catalyst to little or no fluid flow. In asingle bed reactor, if a problem develops with the flow pattern of thefluids passing through the single catalyst bed, the resulting poor flowdistribution will likely continue for the entire length of the bed.

SUMMARY OF THE INVENTION

One aspect of the invention relates to a modular catalyst bed supportthat is not welded to the walls of a reactor, comprising: a latticestructure having a plurality of lattice openings; a plurality of endcappieces attached to the lattice structure to form a lattice skirt; and aplurality of modules inserted into the lattice openings, a modulecomprising: a top surface, the plurality of module top surfaces forminga catalyst support surface; a bottom surface; and an interior surfacethat includes a lip, the lip overlapping one or more edges of thelattice structure when a module is inserted into a lattice opening, theplurality of module interior surfaces forming a flow distributor,wherein the modular catalyst bed support is formed from pieces that canpass through an opening having a diameter of about 28 inches or less.

Another aspect of the invention relates to a kit for assembly of amodular catalyst bed support that is not welded to the walls of areactor, comprising: a plurality of lattice pieces that can be joinedtogether to form a lattice structure having a plurality of latticeopenings; a plurality of endcap pieces capable of being attached to thelattice structure to form a lattice skirt; and a plurality of modulescapable of being inserted into the lattice openings, a modulecomprising: a top surface, the plurality of module top surfaces, whenassembled, forming a catalyst support surface; a bottom surface; and aninterior surface that includes a lip, the lip overlapping one or moreedges of the lattice structure when a module is inserted into a latticeopening, the plurality of module interior surfaces forming a flowdistributor when assembled, wherein the kit for assembly of the modularcatalyst bed support is formed from pieces that can pass through anopening having a diameter of about 28 inches or less.

Still another aspect of the invention relates to a method for dividing acatalyst bed in a reactor without welding a catalyst bed platform to astructural portion of the reactor walls, comprising: passing a pluralityof modular catalyst bed support components into a reactor through anopening having a diameter of about 28 inches or less, the reactor havinga first catalyst bed volume, the modular catalyst bed support componentsincluding lattice components and a plurality of modules; constructing amodular catalyst bed support within the reactor using the modularcatalyst bed support components; supporting the modular catalyst bedsupport with a plurality of bed support hangers; loading a lowercatalyst bed in a lower catalyst bed volume; supporting the modularcatalyst bed support on the lower catalyst bed; and loading an uppercatalyst bed that is supported by the modular catalyst bed support in anupper catalyst bed volume, wherein at least one of the upper catalystbed volume and the lower catalyst bed volume has a length to diameterratio of about 4 to 1 or less.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically depicts a lattice structure according to anembodiment of the invention.

FIG. 2 schematically shows pieces of a lattice structure according to anembodiment of the invention.

FIGS. 3 a (left) and 3 b (both on right) schematically show an endcapaccording to an embodiment of the invention.

FIG. 4 schematically shows a lattice structure with an endcap skirtaccording to an embodiment of the invention.

FIGS. 5 a (left) and 5 b (all three on right) schematically show acatalyst bed module according to an embodiment of the invention in areactor.

FIGS. 6 a (left) and 6 b (right) schematically show additional catalystbed module shapes.

FIG. 7 a schematically shows a lattice structure with a catalyst bedmodule inserted into a lattice opening.

FIG. 7 b shows an assembled modular catalyst bed support according to anembodiment of the invention.

FIG. 8 shows an example of supporting a modular catalyst bed supportwith hangers according to an embodiment of the invention.

FIGS. 9 a, (left), 9 b (center), and 9 c (right) schematically show acatalyst bed hanger according to an embodiment of the invention.

FIG. 10 shows an example of a reactor that includes a modular catalystbed support.

FIG. 11 schematically shows an example of a configuration for a reactortest platform.

FIGS. 12 a (top) and 12 b (bottom) show results from tests in thereactor test platform.

DETAILED DESCRIPTION OF THE EMBODIMENTS Overview

In various embodiments, a modular catalyst bed support is provided thatcan advantageously be used with an existing reactor. For example,addition of a modular catalyst bed support can convert a reactor with asingle catalyst bed to a reactor with two catalyst beds (and it iscontemplated that use of more than one bed support can result in areactor with multiple catalyst beds). A modular catalyst bed support canhave a top surface that is suitable for supporting a catalyst bed, suchas a mesh or wire grating. The bottom of the modular catalyst bedsupport can be suitable for resting on a lower catalyst bed, so that anupper catalyst bed can be supported by the top surface. Adding a modularcatalyst bed support to a reactor can allow for addition of a flowdistributor (such as a distributor tray) and/or a quench system to areactor. The flow distributor and/or quench system can be added in thespace created between the top and bottom surfaces of the modularcatalyst bed support. Addition of a distributor tray can allow forimproved fluid flow within a reactor, which can result in acorresponding increase in the apparent activity of catalyst.

Multiple bed reactors can be used for a variety of refinery processes,e.g., hydroprocessing processes such as hydrodesulfurization processesand cold flow improvement processes. In a multiple bed reactor, adistributor tray or other reactor internal for distributing fluid flowcan be used between beds to redistribute the fluid flow between beds.However, proper operation of a distributor tray typically requires spacebetween the tray and the catalyst bed upstream from the tray, as flowre-distribution typically cannot be achieved in a single catalyst bedsystem.

Adding a catalyst bed to a reactor can pose a variety of challenges. Oneoption for adding a catalyst bed to a reactor can be to weld a catalystbed platform to the structural portion of the reactor walks). In thisoption, the welds to the structural portion of the reactor wall cansupport the weight of the catalyst bed. Adding a catalyst bed to areactor in this manner can require a substantial length of time wherethe reactor is not operational. Additionally, the impact of heating thestructural materials of the reactor wall to a sufficient temperature forwelding may be unclear.

An additional issue with adding a catalyst bed to a reactor can be themethod of access to the inside of the reactor. A typical commercialreactor will generally allow access to the reactor through a top manway,which can have an inner diameter, e.g., from about 18 inches (about 46cm) to about 36 inches (about 91 cm). Some typical manways in olderreactors can have inner diameters from about 20 inches (about 51 cm) toabout 24 inches (about 61 cm). Other common examples of manway diameterscan be at least about 20 inches (about 51 cm), for example at leastabout 22 inches (about 56 cm), at least about 24 inches (about 61 cm),at least about 26 inches (about 66 cm), or at least about 28 inches(about 71 cm). Unless a hole is cut in the reactor wall, the materialsfor adding the catalyst bed to the reactor have to enter the reactorthrough an existing opening. The manway is typically the largestexisting opening available in a reactor for introducing components toadd a catalyst bed. Thus, depending on the embodiment, the pieces forconstructing a catalyst bed platform structure can be pieces that canpass through an opening having a diameter of about 36 inches (about 91cm) or less, for example about 28 inches (about 71 cm) or less, about 26inches (about 66 cm) or less, about 24 inches (about 61 cm) or lessabout 22 inches (about 56 cm) or less, or about 20 inches (about 51 cm)or less.

Another consideration for adding a catalyst bed platform to a reactorcan be the structural integrity of the additional bed platform. Acatalyst bed can have a substantial weight when loaded into a reactor.In addition to this static weight, a catalyst bed platform can alsoexperience a load due to the pressure drop of fluid passing through thecatalyst bed during operation.

In various embodiments, structures, kits, and methods are provided forupgrading a reactor to include an additional catalyst bed. In anembodiment, a modular catalyst bed support can be constructed within areactor to allow for separation of an internal space within a reactorinto multiple catalyst beds. The modular catalyst bed support can beconstructed from pieces (and/or a kit containing pieces) that can enterthe reactor through an existing opening, such as a manway.

One portion of a modular catalyst bed support can be a honeycomb orlattice structure. The lattice structure can be constructed from aplurality of pieces (and/or a kit containing a plurality of pieces) thatcan pass through an existing opening in the reactor. The latticestructure can be formed so that the lattice openings correspond to asingle shape that forms a tessellation, such as hexagons or squares orthe like, or from two or more shapes that together can form atessellation (such as octagons and squares or pentagons and hexagons orthe like). The majority of the openings in the lattice structure cancorrespond to these regular openings. At the edge(s) of the latticestructure, which will typically be at or near the wall(s) of thereactor, half-size or two-thirds-size lattice openings can be used tobetter match/mimic the shape of the lattice to the cross-section of thereactor. The pieces used to form the lattice can be attached, usinginterlocking lips, to reduce or minimize the amount of welding requiredwithin a reactor.

The openings in the lattice can be filled with modular inserts. Themodular inserts can include a foot or base, a top surface for supportinga catalyst bed, and a middle structure that forms a flow distributorwhen combined with the lattice structure and the other modular inserts.The openings in the lattice structure can have an area that is smallerthan the area of an existing opening, such as a manway. This can allowthe modular inserts to pass through such an existing opening in thereactor. Using modules that can pass through an existing opening canreduce or minimize the amount of work required inside the reactor toallow for addition of a catalyst bed.

After assembly, the modular catalyst bed support can be supported byresting on a catalyst bed below the modular catalyst bed support. As aresult, the modular catalyst bed support may not need (and in somepreferred embodiments, does not need) to be supported by the wall(s) ofthe reactor. This can eliminate the need to weld the modular catalystbed support to the wall(s) of the reactor.

The modular catalyst bed support can also include a flow distributor,such as a distributor tray with downcomers. The distributor tray can beformed by plates located between the top and bottom surfaces of theindividual modules. The plates can have a lip that overlaps with one ormore edges of the lattice structure to form the flow distributorstructure. Optionally, a gasket can be included at the location wherethe lip overlaps with the lattice structure. The optional gasket canassist with providing a better seal between the lip and the honeycombstructure, e.g., to reduce any potential leakage through the distributortray.

A modular catalyst bed support can provide a variety of advantagesrelative to a conventional catalyst bed platform welded to a reactorwall. In some embodiments, installing a modular catalyst bed support canreduce the non-operational time required for adding the catalyst bed. Amodular catalyst bed support can be constructed using a scaffold withinthe reactor. Because welding to the structural portion of the reactorwall is not required, the amount of time for installation can bereduced.

In some embodiments, the addition of a catalyst bed platform can improvethe flow characteristics within a reactor. For example, one method forcharacterizing a reactor can be the length of catalyst beds within thereactor versus the diameter of the reactor. A modular catalyst bedsupport can be added to a reactor with any convenient number of existingbeds. Addition of a modular catalyst bed support can allow an existingcatalyst bed to be split into two catalyst beds. For example, in anembodiment involving a reactor with a single catalyst bed, the singlebed can initially have a ratio of catalyst bed length to reactordiameter of at least about 3:1, for example at least about 4:1, at leastabout 5:1, at least about 6:1, at least about 7:1, or at least about8:1. In such an embodiment, a catalyst bed platform can be added to thereactor to allow formation of two catalyst beds, such that at least oneof the resulting catalyst beds can have a ratio of catalyst bed lengthto reactor diameter of about 4:1 or less, for example about 3:1 or less,about 2.5:1 or less, about 2:1 or less, or about 1.5:1 or less.Additionally, or alternately, both resulting catalyst beds can have aratio of catalyst bed length to reactor diameter of about 3:1 or less,for example about 2.5:1 or less or about 2:1 or less. Furtheradditionally or alternately, addition of a modular catalyst bed supportwithin a reactor can reduce the total amount of catalyst loaded into thereactor. However, due to improved flow characteristics, the reducedamount of catalyst can be used more efficiently, leading to a higherapparent activity for the catalyst

Modular Catalyst Bed Support—Lattice Structure

In various embodiments, the modular catalyst bed support can include alattice structure. The lattice structure can serve as a stabilizingstructure for the modular catalyst bed support by providing a lateralconnection between modules. The lattice structure can also assist withmaintaining the location of a module after insertion. The latticestructure can help to reduce/prevent lateral movement of the modules,for example, during lowering of the modular catalyst bed support onto anunderlying catalyst bed prior to operation of the reactor. Duringoperation of a reactor, the modular catalyst bed support can rest on anunderlying catalyst bed. Any lateral motion of modules while in contactwith the catalyst bed could result in an uneven surface for the catalystbed, and therefore a tilted orientation for the modular catalyst bedstructure. A level orientation can be valuable for a flow distributor,such as the flow distributor formed by the middle surfaces of themodules in a modular catalyst bed support.

The lattice structure can include a plurality of openings. In anembodiment, at least a portion of the openings can form a repeatingpattern of openings with similar size, such as a tessellation ofhexagons, squares, octagons/squares, hexagons/pentagons, or otherparallelepiped shapes. Having regular openings in the lattice structurecan reduce the number of different types of modules needed to form thebed support.

It can be desirable to have the shape of the lattice structure roughlymatch the interior shape of the reactor. However, reactors involvingcatalyst beds can often have roughly circular cross sections, while therepeating pattern of openings in the lattice structure can typically bea non-circular shape, such as a hexagon or rectangle. As a result, theoverall shape of the lattice structure can be more like an approximationof a circular shape. In order to improve this approximation, additionaltypes of openings can be included in the lattice structure. For example,for a lattice structure with hexagonal openings, the additional openingshapes can correspond to shapes that are half of a hexagon or two thirdsof a hexagon. The additional shapes can be used at the edges of thelattice structure to reduce the amount of gap between the interiorreactor wall and the edge of the lattice structure. Using thehalf-hexagon and two-thirds-hexagon shapes can improve the ability ofthe lattice structure to fill the reactor cross-section while stillmaintaining a relatively low number of different types of modules. Usingthis type of design, just a few types of modules can be used to add amodular catalyst bed support to a variety of reactors. By contrast, thesize of a lattice structure can be varied to match the internal diameterof each reactor.

In some embodiments, the gap between the lattice structure and theinterior reactor wall can be further reduced by using end cap and/orside plate structures. One surface of the end caps can be designed toprovide a roughly circular perimeter or lattice skirt for the latticestructure, while the inner surface can match the shape formed by thefull and partial lattice openings. In certain embodiments, any gapremaining between the lattice skirt and the inner surface of the reactorwall can then be bridged using a fill material, such as a fiberglassrope material.

Additionally or alternately, the catalyst bed platform can have an outerdiameter deliberately smaller than the inner diameter of the reactor. Inthis type of embodiment, the lattice skirt for the modular catalyst bedsupport can optionally include a lip that protrudes out toward the innerwall of the reactor. The lip can be located at an intermediate locationon the outer surface of the modular catalyst bed support, such ashalfway between the top of the skirt and the bottom of the skirt, or atanother location closer to either the top of the outer surface or closerto the bottom of the outer surface. The gap between the outer surface ofthe skirt and the inner surface of the reactor wall can then be filledwith a material that substantially fills the space between the outersurface of the skirt and the inner surface of the reactor wall. The fillmaterial can be, for example, a glass rope material such as one thatsubstantially fills the space in the gap. The fill material can reduceand/or eliminate the amount of feed that passes around the modularcatalyst bed support, as opposed to passing through the catalyst bed.

The lattice structure can be formed from pieces (and/or a kit containingpieces) or lattice components that can fit through an existing openingin the reactor, such as a manway. One option can be to use interlockingpieces to form a lattice structure. This can reduce the amount ofwelding required inside of a reactor to install the lattice structure.

Catalyst Bed Modules

Another type of component for a modular catalyst bed support can becatalyst bed modules. The openings in the lattice structure can befilled by inserting catalyst bed modules into the lattice openings. Thecatalyst bed modules can include several surfaces. A top surface of thecatalyst bed module can be a surface suitable for supporting a catalystbed. After assembly of the catalyst bed modules into the latticeopenings, the top surfaces of the modules can form a continuous surfacethat prevents (most) catalyst particles from passing through thecontinuous surface. The top surface of the catalyst bed module can beformed from any convenient material for supporting a bed of catalystparticles, such as a mesh or grid having a size smaller than the averagesize of the catalyst particles.

A second surface of the catalyst bed module can be a bottom or footsurface. After insertion of the catalyst bed modules into the lattice,the weight of the modular catalyst bed platform can be supported by theassembled bottom surfaces of the modules, which can rest on a catalystbed below the modular catalyst bed platform. This weight of the modularcatalyst bed platform can include the weight of any catalyst that isbeing supported by the modular catalyst bed platform. The bottom or footsurface can be formed from any convenient material that allows fluid topass through while supporting the modular catalyst bed platform on theunderlying catalyst bed. Examples of suitable materials for the bottomor foot surface can include, but are not limited to, profile wire,perforated plate, a grating or mesh, or the like, or combinationsthereof.

The size of the bottom or foot surface of a catalyst bed module can beselected to allow the foot of the catalyst bed module to pass through alattice opening. This can allow the catalyst bed modules to be assembledinto the lattice opening by inserting the bottom of the modules into theopening. It is noted that this may create a bottom surface for themodular catalyst bed support that is not continuous. Instead, the bottomsurface of the modular catalyst bed support can have a small gap betweenadjacent modules. The gap can approximately correspond to the width ofan edge of the lattice structure. The gap between the bottom surfaces ofcatalyst bed modules can be small enough that particles from theunderlying catalyst bed cannot pass through the gap. For example, acatalyst bed can often include a layer of inert particles at the top ofthe bed. The inert particles can all be of a single size, or the inertparticles can vary in size, such as by having the largest inertparticles at the top of the bed. Typical diameters for inert particlesat the top of a catalyst bed can be at least about 0.25 inches (about0.6 cm), for example at least about 0.5 inches (about 1.3 cm) or atleast about 0.75 inches (about 1.9 cm). The gap between the bottomsurfaces of adjacent modules can be small enough so that the inertparticles at the top of the catalyst bed do not pass through such a gap.

A third surface of the catalyst bed module can be an interior surfacelocated between the top surface and the bottom surface. After assemblyof the catalyst bed modules into the lattice openings, the assembledthird surface(s) can form a flow distributor, such as a distributor traywith downcomers. The interior surfaces for forming the flow distributorcan have a slightly larger size than the lattice opening for thecatalyst bed module. This can be viewed as the interior third surfacehaving a lip around at least a portion of the perimeter of the interiorthird surface. The lip can extend over the edge of the latticestructure.

One option can be to have a lip that extends around the full perimeterof the interior surface of the catalyst bed modules. The lip can extendover the edge of the lattice structure by up to about half of the widthof the lattice side/spine, allowing the interior surface (and thereforethe catalyst bed module) to rest on the surrounding lattice. A lip froman adjacent surface can extend over the edge of a lattice structureside/spine by the same amount to form a continuous surface for the flowdistributor. The lip(s) in combination with the lattice side(s)/spine(s)can form a surface that minimizes and/or prevents leaks through the flowdistributor. Optionally, the lip(s) can extend over the edge of thelattice structure by a sufficient amount so that the lip(s) fromadjacent module(s) are in contact. Additionally or alternately, theconnection between the adjacent surface(s) of the lip(s) and/or thelattice structure can be enhanced, such as by using a glass tapematerial to connect the surface(s) and/or using a gasket to improve theseal(s) between adjacent surface(s).

The surfaces of a catalyst bed module can be connected to one another sothat a volume exists between the top surface and the interior surface. Avolume can additionally or alternately exist between the interiorsurface and the bottom surface. For example, a catalyst bed module canhave at least three surfaces, such as a top surface, an interiorsurface, and a bottom surface. The surfaces can be connected together toform a cage structure, such as by having vertical supports that connectthe surfaces. The volumes between the surfaces in the catalyst bedmodules can improve the operation of the resulting flow distributor thatis formed when the modular catalyst bed support is assembled.

In a conventional design, a catalyst bed platform can be supported byattaching the platform to the structural portion of the reactor wall(s).For an existing reactor, this can require welding the catalyst bedplatform to the bulk structural material that is underneath a protectivecladding or coating. In various embodiments, attachment of the modularcatalyst bed support to the bulk structural material of the reactorwall(s) can be avoided by allowing the modular catalyst bed support tobe supported by a lower catalyst bed. Although the end caps and/orlattice skirt may not contact the interior reactor walls in someembodiments, a fill material (such as glass rope) can be in contact withboth the lattice skirt and the interior reactor wall(s). This can assistin stabilizing the level of the modular catalyst bed support in thereactor. The lattice structure can thus improve the stability of themodular catalyst bed platform, by allowing the modules to move as asingle unit, and/or can assist the modular catalyst bed support inremaining level in the reactor.

Flow Distributor

In a catalyst bed, a fluid flowing through the catalyst bed may have anuneven distribution for a variety of reasons. The length of the catalystbed can be one factor, with longer beds typically having an increasedlikelihood of flow distribution problems. An additional or alternateproblem can be having a low liquid mass flux through the bed, where theamount of liquid flowing through the bed per unit area and per unit timecan be too low to provide uniform flow characteristics. Other additionalor alternate factors that can contribute to a poor flow distribution canbe related to flow bridging within the bed, poor loading of catalystinto the catalyst bed, and/or liquid plugging. A further additional oralternate factor can be that the fluid flowing through the catalyst bedmay have entered the bed with an uneven distribution. A still furtheradditional or alternate factor can be related to changes in the catalystin a catalyst bed as fluid is processed in a reactor. For example, somehydroprocessing reactions can result in formation of “coke” on catalystparticles. The formation of “coke” or other changes in the shape ofcatalyst particles during reaction may alter the space available forfluid flow and/or can lead to random channeling in a catalyst bed. Yet afurther additional or alternate possibility is that local formation of“hot spots” in a catalyst bed may alter the flow of fluid through thebed.

When a fluid flow emerges from a catalyst bed, it can be desirable toredistribute the flow, so that the flow can be more evenly distributedwhen exposed to the next catalyst bed or other reaction stage. This canhave a variety of advantages, such as extending the lifetime of catalystparticles and/or reducing potential hazards, such as localized heatingin a catalyst bed. A variety of flow distribution devices are availablefor use. The devices typically include a plate or tray of some type witha plurality of openings to allow fluid to pass through. If too much flowis incident on a portion of the tray or plate, not all of the fluid maybe able to pass through the openings near the flow. In such situations,the liquid level in the tray or plate can instead equilibrate, resultingin distribution of the flow over a larger portion of the area of thetray or plate. One or more such trays or plates can be used in a flowdistribution device.

During operation, a flow distributor can typically have at least a smallheight of accumulated liquid in or on the device. If a distributiondevice is located immediately adjacent to a catalyst bed, this couldresult in fluid remaining in contact with catalyst for a longer periodof time than desired, and/or stagnation of a portion of the fluid in acatalyst bed. To avoid this situation, it can be desirable to have a gapbetween a catalyst bed and a flow distributor. In a reactor with only asingle catalyst bed, such a gap typically does not exist. As a result,if the fluid flow through a single catalyst bed develops an unevendistribution near the top of the bed, that uneven distribution is likelyto remain through the entire bed.

In various embodiments, inserting a modular catalyst bed support into areactor can allow a catalyst bed to be divided into two beds havingshorter bed lengths. The modular catalyst bed support can also include aflow distributor formed in part by the interior surfaces of the modules.The flow distributor can allow for redistribution of the fluid flow atan intermediate point in the reactor. The gap for allowing properoperation of the flow distributor can be provided by the gaps and/orvolumes between the various surfaces of the modular catalyst bedsupport.

A modular catalyst bed support can be leveled sufficiently toapproximate the levelness of a conventional catalyst bed. In a situationwhere an additional catalyst bed is desired in a single bed reactor, amodular catalyst bed support can allow for difficult and/or expensiveinstallation of an additional catalyst bed without having to support thecatalyst bed, e.g., via welding to the bulk structural portion of thereactor wall(s).

An additional consideration in design of the modular catalyst bedsupport can be the potential difference in expansion of the modularcatalyst bed support relative to the reactor walls during operation. Thethermal expansion characteristics of the modular catalyst bed supportmay differ from those of the reactor wall(s). Although the modularcatalyst bed support typically does not contact the reactor wall(s)directly, a fill material between the platform and the reactor walls canbe in contact. Additionally or alternately, the catalyst supported bythe modular catalyst bed support can be in contact with the reactorwall(s). If differential expansion occurs between the modular catalystbed support and the reactor, frictional forces can place additional loadon the modular catalyst bed support. These additional forces can beaccounted for in the design of the modular catalyst bed support.

Catalyst Loading and Unloading

In order to facilitate catalyst loading and unloading, the modularcatalyst bed support can include a plurality of bed support hangers. Thebed support hangers can provide support for the weight of the modularcatalyst bed support during a catalyst change out. In some embodiments,during a catalyst change out, the catalyst above the modular catalystbed support can be removed before the catalyst below the modularcatalyst bed support. This can allow the bed support hangers to onlyhave to support the weight of the modular catalyst bed support itself,without any extra weight due to catalyst particles.

The bed support hangers can be attached to the modular catalyst bedsupport at any convenient location. In an embodiment, a plurality of bedsupport hangers can be attached to end caps for the modular catalyst bedsupport at various locations around the perimeter of the modularcatalyst bed support. Additionally or alternately, the bed supporthangers can have approximately an “L” shape near the bottom of thehanger, so that a flange or portion of a hanger can be underneath theedge of the modular catalyst bed support. The bed support hangers canhave a sufficient length to attach to both the modular catalyst bedsupport and to a structure above the modular catalyst bed support.Additionally or alternately, the bed support hangers can be attached towires, cables, or rods that are attached to a structure above themodular catalyst bed support. For example, the bed support hangers (orwires attached to the bed support hangers) can be attached to thesupport beams for a flow distributor near the top of the reactor, or anyother convenient choice.

The length of the bed support hangers for the wires connected to the bedsupport hangers) can be sufficient so that the bed support hangers donot provide any support for the weight of the modular catalyst bedsupport after a catalyst bed is loaded underneath the modular catalystbed support. In order to accommodate this, the bed support hangers caninclude a linkage that allows adjustment of the length of the bedsupport hanger. For example, the bed support, hanger can be composed oftwo pieces. A first piece can be a rod that is attached to and thatextends down from a structure toward the top of the reactor. The secondpiece can be attached to and/or extend underneath the modular catalystbed support. The first and second pieces can be attached together usinga joint that can allow for movement of the attachment point, such as athermal expansion slot. When the reactor is empty, the bed supporthanger can be fully extended as it supports the weight of the modularbed support. When a catalyst bed resides underneath the modular catalystbed support, the joint can move within the thermal expansion joint toadjust the length of the hanger, e.g., to match the new position of themodular catalyst bed support. During operation, the thermal expansionjoint can also allow the length of the hanger to adjust, e.g., in theevent that the height of the underlying catalyst bed changes and/or inthe event that the thermal expansion of various objects within thereactor is not the same.

The operation of the hanger supports can be described in relation to acatalyst loading and unloading cycle. As an example, consider a reactorthat includes a modular catalyst bed support. Initially, the reactor cancontain no catalyst. In this state, the modular catalyst bed supportcannot be supported by an underlying catalyst bed, because no catalystis present. Instead, the weight of the modular catalyst bed support canbe supported using a plurality of bed support hangers.

Catalyst can then be added to the reactor. First, a catalyst bed can beadded below the modular catalyst bed support. One or more of the modulesof the modular catalyst bed support can be removed during loading of acatalyst bed underneath the modular catalyst bed support. In oneembodiment, a central module of the modular catalyst bed support can beremoved. Such a central module can be aligned with the center axis ofthe reactor. Creating an opening along the central axis can allow aconventional dense loading machine to be used to fill the first catalystbed. Dense loading can be beneficial, as dense loading can assist withcreating a level surface at the top of a catalyst bed. Because themodular catalyst bed support can rest on the underlying catalyst bedduring hydroprocessing, a level catalyst bed surface can allow for themodular catalyst bed support to also be level. Additionally oralternately, one or more of the modules can be removed, so that sockloading of the catalyst bed can be performed through the resultingopenings. Any other convenient method can additionally or alternately beused. Note that, during loading of the underlying catalyst bed, themodular catalyst bed support can be suspended at a height sufficient toallow catalyst loading. During loading, the modular catalyst bed supportcan be supported by any convenient method. The bed support hangers canbe used to support the modular catalyst bed support. Additionally oralternately, one or more additional chains/cables can be used, such asthose that may be connected to a crane.

After the first catalyst bed is loaded underneath the modular catalystbed support, the modular catalyst bed support can be lowered onto thetop surface of the catalyst bed. The modular catalyst bed support canthen be supported by the underlying catalyst bed rather than by the bedsupport hangers. Optionally, the bed support hangers may not be attachedto the modular catalyst bed support. In such an embodiment, when thecatalyst bed support is resting on the underlying catalyst bed, thebottom of modular catalyst bed support can be separated from, and/or notin contact with, the surfaces of the bed support hangers used to supportthe modular catalyst bed support.

After the first catalyst bed is loaded, any modules removed from themodular catalyst bed support can be inserted into the correspondingopenings. The modules can be inserted either before or after lowering ofthe modular catalyst bed support on to the lower catalyst bed. An uppercatalyst bed can then be introduced above the modular catalyst bedsupport. The catalyst bed above the modular catalyst bed support can beintroduced by any convenient method, such as dense loading and/or sockloading.

For unloading, the catalyst bed above the modular catalyst bed supportcan be removed using any convenient method, such as vacuum removal via atop manway. The catalyst bed above the modular catalyst bed support canbe removed prior to removing the lower catalyst bed. After the uppercatalyst bed is removed, the catalyst bed supporting the modularcatalyst bed support can be removed. The lower catalyst bed can beremoved, for example, using a catalyst exit at the bottom of thereactor. If desired, the lower catalyst bed could also be removed, e.g.,using vacuum techniques by removing one or more of the catalyst modules.

Other Embodiments

Additionally or alternately, the invention can include one or more ofthe following embodiments.

Embodiment 1. A modular catalyst bed support that is not welded to thewalls of a reactor, comprising: a lattice structure having a pluralityof lattice openings; a plurality of endcap pieces attached to thelattice structure to form a lattice skirt; and a plurality of modulesinserted into the lattice openings, a module comprising: atop surface,the plurality of module top surfaces forming a catalyst support surface;a bottom surface; and an interior surface that includes a lip, the lipoverlapping one or more edges of the lattice structure when a module isinserted into a lattice opening, the plurality of module interiorsurfaces forming a flow distributor, wherein the modular catalyst bedsupport is formed from pieces that can pass through an opening having adiameter of about 28 inches or less, preferably 24 inches or less.

Embodiment 2. The modular catalyst bed support of embodiment 1, whereinthe plurality of module bottom surfaces are suitable for supporting theweight of the modular catalyst bed support, and/or wherein a majority ofthe openings in the lattice structure correspond to a shape that forms atessellation.

Embodiment 3. The modular catalyst bed support of any one of the aboveembodiments, wherein the lattice structure is optionally assembled frominterlocking pieces without welding and includes at least two shapes oflattice openings, the lattice structure preferably including hexagonalshapes, half-hexagonal shapes, and two-third hexagonal shapes.

Embodiment 4. The modular catalyst bed support of any one of the aboveembodiments, further comprising a plurality of bed support hangers.

Embodiment 5. The modular catalyst bed support of embodiment 5, whereinat least a portion of a bed support hanger is underneath the latticeskirt.

Embodiment 6. The modular catalyst bed support of any one of the aboveembodiments, further comprising a fill material surrounding a portion ofthe lattice skirt, the fill material being in contact with the latticeskirt and in contact with an interior wall of the reactor.

Embodiment 7. The modular catalyst bed support of any one of the aboveembodiments, wherein the plurality of modules further comprise an openvolume between the top surface and the interior surface.

Embodiment 8. The modular catalyst bed support of any one of the aboveembodiments, wherein the lattice openings in the lattice structure havea smaller area than an opening that the modular catalyst bed supportpieces are passed through to enter the reactor.

Embodiment 9. A kit for assembly of a modular catalyst bed support thatis not welded to the walls of a reactor, comprising: a plurality oflattice pieces that can be joined together to form a lattice structurehaving a plurality of lattice openings; a plurality of endcap piecescapable of being attached to the lattice structure to form a latticeskirt; and a plurality of modules capable of being inserted into thelattice openings, a module comprising: a top surface, the plurality ofmodule top surfaces, when assembled, forming a catalyst support surface;a bottom surface; and an interior surface that includes a lip, the lipoverlapping one or more edges of the lattice structure when a module isinserted into a lattice opening, the plurality of module interiorsurfaces forming a flow distributor when assembled, wherein the kit forassembly of the modular catalyst bed support is formed from pieces thatcan pass through an opening having a diameter of about 28 inches orless.

Embodiment 10. The modular catalyst bed support kit of embodiment 9,wherein the kit is formed from pieces that can pass through an openinghaving a diameter of about 24 inches or less, and/or wherein the latticestructure is assembled from interlocking pieces without welding.

Embodiment 11. A method for dividing a catalyst bed in a reactor withoutwelding a catalyst bed platform to a structural portion of the reactorwalls, comprising: passing a plurality of modular catalyst bed supportcomponents into a reactor through an opening having a diameter of about28 inches or less, the reactor having a first catalyst bed volume, themodular catalyst bed support components including lattice components anda plurality of modules; constructing a modular catalyst bed supportwithin the reactor using the modular catalyst bed support components;supporting the modular catalyst bed support with a plurality of bedsupport hangers; loading a lower catalyst bed in a lower catalyst bedvolume; supporting the modular catalyst bed support on the lowercatalyst bed; and loading an upper catalyst bed that is supported by themodular catalyst bed support in an upper catalyst bed volume.

Embodiment 12. The method of embodiment 11, wherein a catalyst bedvolume in the reactor has a length to diameter ratio of at least about6:1 prior to insertion of the modular catalyst bed support, and at leastone of the upper catalyst bed volume and the lower catalyst bed volumehas a length to diameter ratio of about 2.5 to 1 or less.

Embodiment 13. The method of embodiment 11 or embodiment 12, whereinloading an upper catalyst bed comprises inserting a plurality of foamelements during loading of the upper catalyst bed, inserting a layer ofinert particles during loading of the upper catalyst bed, or acombination thereof.

Embodiment 14. The method of any one of embodiments 11-13, whereinconstructing a modular catalyst bed support comprises: constructing alattice structure from the lattice components, the lattice structureincluding a plurality of openings; inserting the modules into theplurality of openings; optionally assembling a plurality of endcapsaround the lattice structure to form a lattice skirt; and optionallyinserting a material in a gap between the lattice skirt and an innerwall of the reactor.

Embodiment 15. The method of any one of embodiments 11-14, whereinloading the lower catalyst bed in the lower catalyst volume comprises:supporting the modular catalyst bed support at a height within thereactor; loading the lower catalyst bed below the modular catalyst bedsupport; and lowering the modular catalyst bed support so that a bottomsurface of the catalyst bed support contacts the lower catalyst bed.

EXAMPLES Example of Modular Catalyst Bed Support

The following example will schematically illustrate various pieces of amodular catalyst bed support (that may form a kit) according to anembodiment of the invention. The assembly of such pieces into a modularcatalyst bed support according to an embodiment of the invention is alsoschematically illustrated below.

FIG. 1 shows an example of a lattice structure 100 suitable for use inan embodiment of the invention. The lattice structure 100 in FIG. 1 isdepicted before end caps have been added to the structure. In FIG. 1,the majority of the openings 110 in the lattice structure can correspondto a repeating pattern of hexagons. Toward the edge of the latticestructure, half-hexagon shapes 112 and two-third-hexagon shapes 113 canalso be used to provide a better approximation of a circular shape.

FIG. 2 shows an example of individual lattice pieces 201 and 202 forconstructing a lattice structure. In the example shown in FIG. 2, theindividual lattice pieces can resemble a series of half-hexagon shapes,e.g., which can be contained in a kit for assembly of a modular catalystbed support according to the invention. Lattice pieces 201 and 202 canbe joined together to form hexagonal openings, such as openings 110 fromFIG. 1. Lattice piece 201 can be composed of full hexagonal sides 221and interlocking spines 223. Similarly lattice piece 202 can includefull hexagonal sides 222 and interlocking spines 224. When a latticestructure is assembled, e.g., from a kit containing lattice pieces, theinterlocking spines 223 and 224 from adjacent pieces can overlap,leading to a stable structure. Depending on the embodiment, one or morefasteners can be optionally used to secure adjacent lattice pieces, orthe fastener(s) may be unnecessary. The combination of interlockingspines 223 and 224 from adjacent pieces can form an interlockingstructure that provides the remaining sides for the hexagonal latticeshapes in the lattice structure. In the embodiment shown in FIG. 2,lattice piece 201 may not be a mirror image of lattice piece 202; e.g.,lattice piece 202 may instead be rotated by 180 degrees relative tolattice piece 201.

FIGS. 3 a and 3 b show examples of structures that can be used asendcaps for the lattice structure. FIG. 3 a shows an embodiment of anassembled endcap structure 330. The endcap structure 330 can include atleast three surfaces. Top surface 331 can form part of a catalystsupport grid. Bottom surface 333 can form part of the bottom or foot ofthe modular bed support. Interior surface 335 can form part of a flowdistributor, such as a distributor tray.

In some embodiments, endcap structure 330 can be too large to passthrough a manway or other existing opening in a reactor. In suchembodiments, an endcap structure 330 can be passed into a reactor inpieces and then assembled inside the reactor. FIG. 3 b shows an exampleof how the side plate 340 for endcap structure 330 can be divided intoan upper side plate 342 and a lower side plate 344. FIG. 3 b alsoprovides a less restricted view of additional structure on the interiorsurface 335. In the embodiment shown in FIG. 3 b, side plate 340 can bedivided at the interior surface 335 of the endcap structure 330. Upperside plate 342 can include downcomers 338 and additional vapor chimneys339. The downcomers 338 and additional vapor chimneys 339 can extendbelow the bottom of upper side plate 342. These extensions can beinserted into corresponding openings 348 and 349 in lower side plate344. In addition to allowing fluid to pass through the flow distributor,this can assist in improving the structural stability of endcapstructure 330, e.g., without requiring welding of the individual pieces.

FIG. 4 shows an example of adding endcap structures 330 to a latticestructure 100. Adding endcap structures 330 to a lattice structure 100can provide a lattice skirt for a modular catalyst bed support. Theendcap structures 330 in FIG. 4 include a lip 446 around the perimeteror lattice skirt of the modular catalyst bed support. The outer lip 446can have a closer approach to the interior reactor wall than the rest ofthe endcap skirt. This can allow the outer lip 446 to support theinsertion of a fill material between the endcap structures 330 and theinterior wall of a reactor. A glass rope is one example of a fillmaterial than can be used.

FIGS. 5 a and 5 b schematically show an embodiment of a module 550,e.g., from a kit containing multiple modules, for a modular catalyst bedsupport. FIG. 5 a shows an assembled module 550. The assembled module550 can include at least three surfaces. Top surface or arid 551 canform part of a catalyst support grid. Bottom surface 553 can form partof the bottom or foot of the modular bed support. Interior surface 555can form part of a flow distributor, such as a distributor tray.Interior surface 555 can additionally or alternately include downcomers558 to allow fluids to pass through the distributor tray. Vaporchimney(s) 559 can further additionally or alternately be included.

FIG. 5 b shows another perspective view of various components of amodule 550. The top surface 551 and bottom surface 553 are shownseparately from the skeleton or “can” structure 560 of the module 550 tofacilitate viewing of other portions of the module 550. In the skeletonstructure 560, open volume 561 is provided above and below inferiorsurface 555. This open volume can improve the operation of the flowdistributor that can be formed from the combination of the interiorsurfaces of interconnected modules. Flanges 562 at the top of skeletonstructure 560 can be used to bolt together adjacent modules. Theinterior surface 555 can include a lip 556, which can advantageouslyassist in forming a seal between adjacent interior surfaces. The lip mayalso overlap the lattice structure 100, e.g., to provide additionalstability.

FIGS. 6 a and 6 b show alternate module geometries that can be used toform a modular catalyst bed support. Toward the edge of a latticestructure, the geometry of the reactor may create a gap large enough tobe desirable to fill, yet too small to permit a full sized module. Inthis situation, a module with an alternate module geometry can be used.For the hexagonal lattice structure embodiment shown in FIG. 1, onealternate module geometry can correspond to a half-size module 670. Thetop surface 671, bottom surface 673, and interior surface 675 can besimilar to the corresponding surfaces in a full size module. Anotheralternate module geometry can correspond to a two-third-size module 672.

FIG. 7 a schematically shows a lattice structure 100 with endcaps 330after insertion of a module 550 in the central opening of the latticestructure. Optionally, the lip of module 550 can be further sealedagainst lattice structure 100 using a suitable material, such as glasstape. Optionally, the lips of adjacent modules 550 can be further sealedagainst each other using a suitable material, such as glass tape.Modules 550 can be inserted into the other full size openings 110, whilealternative geometry modules can be used to fill the half-size (670 inFIG. 6 a) and/or two-third size (672 in FIG. 6 b) openings. Insertingmodules into the remaining openings can result in formation of a modularcatalyst bed support 780, as shown in FIG. 7 b.

FIG. 8 schematically shows an example of supporting a modular catalystbed support 780 using bed support hangers 890. In the embodiment shownin FIG. 8, the bed support hangers 890 can be attached to the supportbeams for an upper distributor tray 885 in a reactor. The bed supporthangers 890 have an L-shaped flange (not shown) at the bottom underneaththe modular catalyst bed support 780.

FIGS. 9 a to 9 c schematically provide a more detailed view of anembodiment of a bed support hanger. FIG. 9 a shows the lower portion 891of an embodiment of a bed support hanger. The L-shaped flange 892 can beunderneath a modular catalyst bed support, e.g., to provide support whena lower catalyst bed is not present. As shown in FIG. 9 b, the topgrooved structures 893 can combine with a grooved structure 895 of upperportion 896 to provide a thermal expansion slot connection 894. This canallow the bed support hanger to change in length if necessary, such asdue to differential thermal expansion and/or settlement by theunderlying catalyst bed. FIG. 9 c schematically shows a more detailedview of the top U-shaped structure 898 of upper portion 896. TheU-shaped structure 898 can be bolted to an existing beam, such as asupport beam from an upper distributor tray. Additionally oralternately, the U-shaped structure 898 can be bolted to any otherconvenient support structure that has a sufficient elevation in thereactor, including existing structures within the reactor and/oradditional structures added for the purpose of supporting the bedsupport hangers.

FIG. 10 schematically shows an example of a reactor that includes amodular catalyst bed support. In FIG. 10, reactor 1000 can include twocatalyst beds. The first catalyst bed 1010 can be supported by themodular catalyst bed support 1020. The modular catalyst bed support 1020can be supported by second catalyst bed 1030. A top flow distributor inthe reactor is also shown as reference numeral 1040. Bed support hangersfor the modular catalyst bed support 1020 are not shown. Top manway 1050can be used for introducing the pieces (e.g., from a kit) for assemblingmodular catalyst bed support 1020 into the reactor 1000. Duringhydroprocessing, fluids introduced into the reactor can pass through topflow distributor 1040. The fluids can then be exposed to hydroprocessingconditions in the presence of first catalyst bed 1010. The fluids can bere-distributed, e.g., by a flow distributor, within modular catalyst bedsupport 1040. The fluids can then be exposed to hydroprocessingconditions in the presence of second catalyst bed 1030. The effluentfrom the hydroprocessing reaction can exit the reactor 1000 via outlet1060.

Example of Use in Hydroprocessing

In this example, a modular catalyst bed support can be used to add acatalyst bed to a hydroprocessing reactor. For purposes of this example,a reactor that originally has a single catalyst bed can be used. Duringa catalyst turn-around, the modular catalyst bed support can beconstructed within the reactor. The reactor can then be loaded with twobeds of catalyst. A first hydroprocessing catalyst can be loaded in thelower (original) catalyst bed, while a second hydroprocessing catalystcan be loaded on the new catalyst bed platform. The first and secondhydroprocessing catalysts can be the same or different. Optionally, thefirst and second hydroprocessing catalysts can be catalyst systems, andcan comprise a series of catalysts stacked on top of one another. Thefirst and second hydroprocessing catalysts can be selected from anyconvenient catalyst/system for hydrotreatment, catalytic dewaxing,hydrofinishing, and/or other hydroprocessing functions.

In this example, the reactor can be configured for dieselhydroprocessing. Insertion of the modular catalyst bed support can allowfor hydrotreatment of a diesel feed using two separate types ofcatalysts, or both catalyst beds can include similar type of catalyst(e.g., the same catalyst). In this example, the first and secondhydroprocessing catalysts can be selected to both be dieselhydrotreatment catalysts. The reactor can then be operated undereffective hydrotreatment conditions. In certain applications, a modularcatalyst bed support can be added to a reactor used for hydrocracking,chemicals processing, and/or other types of catalytic processes that canbenefit from the addition of a catalyst bed to a reactor.

Additionally or alternately, a modular catalyst bed support can beincluded in a reactor having any convenient number of beds. For example,in a reactor with two catalyst beds, a modular catalyst bed support canbe added to split either (or both) of the existing beds. A modularcatalyst bed support can be similarly employed in a reactor with threeor more catalyst beds.

In various embodiments, a suitable catalyst for hydrotreatment, aromaticsaturation, and/or hydrofinishing can be a catalyst comprising one ormore Group VIII and/or Group VIB metals, optionally on a support.Suitable metal oxide supports can include low acidic oxides such assilica, alumina, silica-aluminas, titania, or the like, or combinationsthereof. The metal(s), which may be supported or in the form of a bulkcatalyst, can include Co, Ni, Fe, Mo, W, Pt, Pd, Rh, Ir, andcombinations thereof. In one embodiment, the metal can be Pt and/or Pd.Additionally or alternately, the metal can be one or more of Co, Ni, Mo,and W, such as CoMo, NiMo, NiNV, or NiMoW. In such embodiments, theamount of metal(s), either individually or in mixtures, can be at leastabout 0.1 wt %, for example at least about 0.25 wt %, at least about 0.5wt %, at least about 0.6 wt %, at least about 0.75 wt %, or at leastabout 1 wt %, based on the weight of the catalyst composition.Additionally or alternately, the amount of metal(s), either individuallyor in mixtures, can be about 35 wt % or less, for example about 30 wt %or less, about 25 wt % or less, about 20 wt % or less, about 15 wt % orless, about 10 wt % or less, about 5 wt % or less, or about 3 wt % orless, based on the weight of the catalyst composition. In embodimentswherein the metal is a supported noble metal, the amount of metal(s) cantypically be less than about 2 wt %, for example less than about 1 wt %,based on the weight of the catalyst composition. Additionally oralternately in such embodiments, the amount of metal(s) can be about 0.9wt % or less, for example about 0.75 wt % or less or about 0.6 wt % orless, based on the weight of the catalyst composition. The amounts ofmetals may be measured by methods specified by ASTM for individualmetals including atomic absorption spectroscopy and/or inductivelycoupled plasma-atomic emission spectrometry. In some embodiments, thehydrotreating catalyst can be catalyst with a relatively low level ofhydrogenation activity, such as a catalyst containing Co as a Group VIIImetal, as opposed to a catalyst containing Ni, Pt, and/or Pd as a GroupVIII metal. In certain embodiments otherwise characterized ashydrotreating embodiments, at least a portion of one or more catalystbeds or stages therein can include a type of catalyst other thanstrictly a hydrotreating catalyst, such as a hydrocracking catalyst, ahydrofinishing catalyst, and/or a dewaxing catalyst.

The hydrotreating conditions can include one or more of: a temperatureof at least about 260° C., for example at least about 300° C.; atemperature of about 425° C. or less, for example about 400° C. or lessor about 350° C. or less; a liquid hourly space velocity (LHSV) of atleast about 0.1 hr⁻¹, for example at least about 0.3 hr⁻¹, at leastabout 0.5 hr⁻¹, or at least about 1.0 hr⁻¹; an LHSV of about 10.0 hr⁻¹or less, for example about 5.0 hr⁻¹ or less or about 2.5 hr⁻¹ or less; ahydrogen partial pressure in the reactor from about 200 psig (about 1.4MPag) to about 3000 psig (about 20.7 MPag), for example about 400 psig(about 2.8 MPag) to about 2000

psig (about 13.8 MPag); a hydrogen to feed ratio (hydrogen treat gasrate) from about 500 scf/bbl (about 85 Nm³/m³) to about 10000 scf/bbl(about 1700 Nm³/m³), for example from about 1000 scf/bbl (about 170Nm³/m³) to about 5000 scf/bbl (about 850 Sm³/m³).

Additional Configurations—Virtual Flow Distributor

One of the potential reasons to add a modular catalyst bed support canbe to allow for the introduction of an additional flow distributor to areactor. An additional flow distributor can improve the efficiency ofcatalyst usage in a reactor. In some reactors, the reactivity of acatalyst in a reactor can be lower than what would be expected based onsmall scale testing. This can be due to inefficiencies in how fluids aredistributed in the reactor. If part of the inefficiency is due to poordistribution of liquids within the reactor, a flow distributor canimprove the contact of liquids with the catalyst.

Additional structures and/or catalyst configurations can be used toimprove catalyst efficiency within a reactor. These structures and/orcatalyst configurations can be used in conjunction with a modularcatalyst bed support, and/or in a reactor that does not include amodular catalyst bed support.

In some situations, it may be desirable to introduce an additional flowdistributor into a reactor without having to introduce a separatecatalyst bed platform. A typical flow distribution device, such as adistributor tray, can typically benefit from having an open volume aboveand below the distributor tray. This can increase the amount of catalystto be removed from the reactor in order to add the distributor tray.This can additionally or alternately reduce the amount of benefitderived from the distributor tray, as the increased catalyst efficiencycan be offset by the loss of some catalyst volume.

In an embodiment, a virtual flow distributor can be introduced into areactor without requiring addition of a catalyst bed platform or modularcatalyst bed support. A virtual flow distributor can be created, forinstance, using one or more foam elements. The foam elements can be madeof a porous and/or reticulated foam. The porous foam elements can take aliquid and/or vapor stream from above the foam and re-distribute thestream over a broader area.

In embodiments where one or more foam elements are introduced into areactor, one option can involve tightly packing a layer of foamelements, e.g., such that substantially all liquid and gas passing downthrough the reactor can pass through a foam element. Alternately, two ormore layers of foam elements can be stacked in overlapping layers. Thetwo or more layers can be stacked, e.g., so that liquid stream passingvertically through a reactor can contact at least one foam element alongthe path of the liquid. For foam elements stacked above one another, itis noted that fluid entering a first foam element may be re-distributedand exit the first foam element above a second foam element. This fluidcan be re-distributed again by the second foam element.

As an example of use, foam elements can be used to form a virtual flowdistributor in a reactor. A first portion of catalyst can be loaded intothe reactor. An inert material can then be loaded above the firstportion of catalyst, such as about 0.25 inch (about 0.6 cm) diameterballs. The inert layer can assist with preventing movement of the foamelements relative to the catalyst beds and/or relative to each other.The inert layer can have a thickness of about 1 cm to about 20 cm ormore. A layer of foam elements can then be placed on the first catalystbed. The foam elements can have a thickness of about 1 cm to about 10cm, so the corresponding layer can have a similar thickness. Additionalinert materials can be added to fill the space between the foam elementsand/or to form a layer of inert materials above the foam elements.Additional layers of foam elements and inert materials can then beinserted until a desired number of foam elements layers are achieved. Asecond layer of catalyst can then be placed above the final inertmaterial layer.

FIG. 11 shows an example of a test column 1100 that was used toinvestigate use of foam elements for re-distribution of fluids. In thetest column represented by FIG. 11, a point source 1105 of a liquid wasintroduced into test column 1100. The point source 1105 of liquid had astream size that was narrow relative to the width of the test column. Inone configuration, layers 1120, 1125, and 1130 were layers of particlesof a size typical for catalyst particles. In a second configuration,layers 1120 and 1130 were layers of the typical size particles. However,in the second configuration, layer 1125 was a porous foam element havinga width that approximately matched the column. As a result, the porousfoam element used in the second configuration represented a tightlypacked foam element layer that substantially all liquids and gases inthe reactor had to pass through. In each configuration, the catalystlayer 1130 was supported by catalyst support grid 1140. At the outlet ofthe test column 1100 was a patternator 1150 for capturing the liquidoutput, which allowed the output of the column to be characterized asbeing in one of 16 bins.

FIG. 12 a shows the liquid distribution measured using the patternatorfor the first configuration containing only catalyst beds. As shown inFIG. 12 a, the output flow for the first configuration was heavilyconcentrated in only a few bins. This indicates a poor distributionrelative to an idealized distribution where each bin would have receivedroughly the same amount of liquid. FIG. 12 b shows the liquiddistribution for the second configuration, where layer 1125 contained afoam element instead of a catalyst layer. FIG. 12 b indicates that,though some variation can still exist in the amount of liquid reachingeach bin of the patternator, the amount of difference between bins issharply reduced. The pattern shown in FIG. 12 b appears to be a moresuitable pattern for achieving efficient use of a catalyst layer duringa catalytic process.

Additional/Alternate Configurations Mitigating Hydrogen Starvation

An additional or alternate potential cause for inefficient use ofhydroprocessing catalyst can be lack of availability of hydrogen withina catalyst bed. During hydroprocessing, a desired hydroprocessingreaction can be dependent on the availability of hydrogen in thereaction environment. If the amount of hydrogen in a catalyst bedbecomes depleted in a local region, the feedstock flowing through thatlocal region may not be exposed to the desired reaction conditions.Instead, the feedstock may undergo no reaction, and/or the feedstock mayreact in a non-desirable manner, such as by forming coke.

A feedstock may additionally or alternately not flow through a catalystbed in an evenly distributed manner. Instead, a feedstock maypreferentially flow through certain portions of the catalyst in acatalyst bed for one or more of a variety of reasons. If this occurs,the amount of hydrogen in the preferential flow regions may becomedepleted.

In an embodiment, one option for mitigating hydrogen depletion can be toinclude an intermediate zone/layer in a catalyst bed containing(relatively) inert packing materials. In the inert packing layer,hydrogen consumption can be reduced or stopped entirely. This can allowthe opportunity for hydrogen present in a flow to distribute laterally,thus allowing the hydrogen concentration to build up in an area depleteddue to preferential flow. The zone of inert packing materials canadditionally or alternately help to reduce the amount of preferentialflow, e.g., by redistributing the flow within the catalyst bed.

An inert packing zone/layer within a catalyst bed can be created duringloading of a catalyst bed. First, a layer of catalyst can be loaded. Theinert layer can then be added by loading any convenient type of inertmaterials. One option can be to use graded layers of inert materials.For example, the inert materials can be spherical or approximatelyspherical particles. The inert spheres loaded on top of the catalyst canhave a smaller size, such as about 1/32inches (about 0.08 cm). Two ormore types of inert spheres can be loaded in the layer, so that largerspheres such as having about a 1-inch (about 2.5 cm) can be used in themiddle of the inert layer. The order of the sphere sizes can then bereversed, so that the smaller spheres will be at the top of the inertlayer. The remainder of the catalyst for the catalyst bed can then beloaded on top of the inert layer.

While the above example describes the use of spherical particles, anyother convenient shape of inert particles can be used. Such shapes caninclude multi-lobe shapes, such as trilobes. Wagon wheel and/or annularshapes can additionally or alternately be used, and any gradations maybe based on diameter, shape, or both. In addition to inert particles,the inert zone/layer may include inert metal slats/gutters.

One or more inert layers can be included at any convenient locationwithin a catalyst bed. In addition to inert layers within a bed, aninert layer at the top of a catalyst bed may also assist in distributinga fluid flow more evenly in the catalyst bed from the start.

While the present invention has been described and illustrated byreference to particular embodiments, those of ordinary skill in the artwill appreciate that the invention can lend itself to variations notnecessarily illustrated herein. For this reason, then, reference shouldbe made solely to the appended claims for purposes of determining theenforceable scope of the present invention.

1. A modular catalyst bed support that is not welded to the walls of areactor, comprising: a lattice structure having a plurality of latticeopenings; a plurality of endcap pieces attached to the lattice structureto form a lattice skirt; and a plurality of modules inserted into thelattice openings, a module comprising: a top surface, the plurality ofmodule top surfaces forming a catalyst support surface; a bottomsurface; and an interior surface that includes a lip, the lipoverlapping one or more edges of the lattice structure when a module isinserted into a lattice opening, the plurality of module interiorsurfaces forming a flow distributor, wherein the modular catalyst bedsupport is formed from pieces that can pass through an opening having adiameter of about 28 inches or less.
 2. The modular catalyst bed supportof claim 1, wherein the plurality of module bottom surfaces are suitablefor supporting the weight of the modular catalyst bed support.
 3. Themodular catalyst bed support of claim 1, wherein a majority of heopenings in the lattice structure correspond to a shape that forms atessellation.
 4. The modular catalyst bed support of claim 1, whereinthe lattice structure is optionally assembled from interlocking pieceswithout welding and includes at least two shapes of lattice openingscorresponding to at least one of hexagonal shapes, half-hexagonalshapes, and two-third hexagonal shapes.
 5. The modular catalyst bedsupport of claim 1, further comprising a plurality of bed supporthangers, wherein at least a portion of a bed support hanger isunderneath the lattice skirt.
 6. The modular catalyst bed support ofclaim 1, wherein the modular catalyst bed support is formed from piecesthat can pass through an opening having a diameter of about 24 inches orless.
 7. The modular catalyst bed support of claim 1, further comprisinga fill material surrounding a portion of the lattice skirt, the fillmaterial being in contact with the lattice skirt and in contact with aninterior wall of the reactor.
 8. The modular catalyst bed support ofclaim 1, wherein the plurality of modules further comprise an openvolume between the top surface and the interior surface.
 9. The modularcatalyst bed support of claim 1, wherein the lattice openings in thelattice structure have a smaller area than an opening that the modularcatalyst bed support pieces are passed through to enter the reactor. 10.A kit for assembly of a modular catalyst bed support that is not weldedto the walls of a reactor, comprising: a plurality of lattice piecesthat can be joined together to form a lattice structure having aplurality of lattice openings; a plurality of endcap pieces capable ofbeing attached to the lattice structure to form a lattice skirt; and aplurality of modules capable of being inserted into the latticeopenings, a module comprising: a top surface, the plurality of moduletop surfaces, when assembled, forming a catalyst support surface; abottom surface; and an interior surface that includes a lip, the lipoverlapping one or more edges of the lattice structure when a module isinserted into a lattice opening, the plurality of module interiorsurfaces forming a flow distributor when assembled, wherein the kit forassembly of the modular catalyst bed support is formed from pieces thatcan pass through an opening having a diameter of about 28 inches orless.
 11. The kit for assembly of a modular catalyst bed support ofclaim 10, wherein the kit for assembly of the modular catalyst bedsupport is formed from pieces that can pass through an opening having adiameter of about 24 inches or less.
 12. The kit for assembly of amodular catalyst bed support of claim 10, wherein the lattice structureis assembled from interlocking pieces without welding.
 13. A method fordividing a catalyst bed in a reactor without welding a catalyst bedplatform to a structural portion of the reactor walls, comprising:passing a plurality of modular catalyst bed support components into areactor through an opening having a diameter of about 28 inches or less,the reactor having a first catalyst bed volume, the modular catalyst bedsupport components including lattice components and a plurality ofmodules; constructing a modular catalyst bed support within he reactorusing the modular catalyst bed support components; supporting themodular catalyst bed support with a plurality of bed support hangers;loading a lower catalyst bed in a lower catalyst bed volume; supportingthe modular catalyst bed support on the lower catalyst bed; and loadingan upper catalyst bed that is supported by the modular catalyst bedsupport in an upper catalyst bed volume.
 14. The method of claim 13,wherein a catalyst bed volume in the reactor has a length to diameterratio of at least about 6:1 prior to insertion of the modular catalystbed support, and at least one of the upper catalyst bed volume and thelower catalyst bed volume has a length to diameter ratio of about 2.5 to1 or less.
 15. The method of claim 13, wherein loading an upper catalystbed comprises inserting a plurality of foam elements during loading ofthe upper catalyst bed.
 16. The method of claim 13, wherein loading anupper catalyst bed comprises inserting a layer of inert particles duringloading of the upper catalyst bed.
 17. The method of claim 13, whereinconstructing a modular catalyst bed support comprises: constructing alattice structure from the lattice components, the lattice structureincluding a plurality of openings; and inserting the modules into theplurality of openings.
 18. The method of claim 17, wherein constructinga modular catalyst bed support further comprises assembling a pluralityof endcaps around the lattice structure to form a lattice skirt.
 19. Themethod of claim 18, wherein supporting the modular catalyst bed supporton a lower catalyst bed comprises supporting the modular catalyst bedsupport without the lattice skirt contacting an inner wall of thereactor so that a gap is formed between the lattice skirt and the innerwall of the reactor, the method further comprising inserting a fillmaterial in the gap between the lattice skirt and the inner wall of thereactor.
 20. The method of claim 13, wherein loading the lower catalystbed in the lower catalyst volume comprises: supporting the modularcatalyst bed support at a height within the reactor; loading the lowercatalyst bed below the modular catalyst bed support; and lowering themodular catalyst bed support so that a bottom surface of the catalystbed support contacts the lower catalyst bed.